The present embodiments relate to apparatus and methods for providing and controlling air flow and heat transfer across products in freezing systems for example, used with food products.
Known freezers have a fan or a plurality of fans to provide a convective airflow environment to accelerate the freezing rate of products, such as food products, being processed in the freezer. Fans require electrical energy to operate and contribute the thermal loads to the freezing processes which reduces the overall efficiency of the freezer. Therefore, the use of fewer fans is advantageous.
It is also know to pulse or oscillate a flow of gas across the surface of a product for increasing convective surface heat transfer co-efficients. Such a pulsing or oscillating flow of gas can require equipment that is expensive to maintain and more difficult to operate under low temperatures. Sanitation may also be more problematic with such systems.
However, using a single fan assembly to create the same oscillating or pulsating flow is not known, would be less expensive to implement and would reduce sanitary problems for which the food industry is particularly concerned.
The present inventive embodiments provide a freezer which provides the oscillating or pulsing flow of the gas with a single fan assembly.